FE(III) AND TRANSITION METALS TRANSPORT

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 禾本科植物从碱性土壤中吸收Fe(III)和其他过渡金属的方式是分泌植物铁素载体、金属螯合剂，然后用YS1转运蛋白将植物铁质载体金属复合体运回质膜(黄条1)。对这种转运蛋白的更多了解可能会增加营养不良、缺铁的世界的铁源。已在非洲爪哇卵母细胞中进行了功能鉴定。电化学H+梯度被认为是驱动植物铁载体-金属络合物吸收的原因。这些结果最近受到了质疑，因为用于驱动摄取的胞外酸化在非洲爪哇卵母细胞中产生了一种具有良好特征的人工制品。我们正在其他异源系统中表达转运蛋白，不太容易出现这种人工制品，特别是哺乳动物和昆虫细胞系，用于表征转运蛋白的目的。结合电化学通量测量的功能表征将能够识别转运体的化学计量比。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Graminaceous plants take up Fe(III) and other transition metals from alkaline soils by secreting phytosiderophores, metal chelators, and then transporting the phytosiderophore-metal complex back across the plasma membrane with YS1 transporters, (Yellow-striped 1). Understanding more about this transporter could lead to an increased source of iron for the under-nourished, iron deficient world. Functional characterization has been performed in Xenopus oocytes. The electrochemical H+ gradient is thought to drive uptake of the phytosiderophore-metal complex. These results have recently been questioned due to the fact that the extracellular acidification used to drive uptake generates a well-characterized artifact in the Xenopus oocytes. We are in the process of expressing the transporters in other heterologous systems, less prone to this artifact, specifically mammalian and insect cell lines for the purpose of characterizing transport. Functional characterization in combination with electrochemical flux measurements will enable identification of the stoichiometry of the transporter.